Arshi Tengri, the "Hermit God", is a god who is associated with the [Fire worship|fire ritual] as practiced in Mongolian Buddhism. The epithet is found in a prayer by the 18th-century lama Mergen Gegen Lubsangdambijalsan, where it is added to the name of the "Khan of the fire". "Arshi" derives from Sanskrit rsi; "tngri" refers to the 99 tngri or Mongolian deities.
References
Arshi Tengri Wikipedia(Text) CC BY-SA